Tunable refraction power by mutual rotation of helical lens parts

摘要

This paper presents a refractive optical system consisting of two lens bodies with helical surface structures, which allows for tuning the optical refraction power by means of a mutual rotation of the lens bodies around the optical axis. Thus, the refraction power can be tuned continuously in a certain range. The helical surfaces are shaped by changing the radius of curvature as a function of to the polar angle. Combination of such two surfaces results in an optics with refraction power being tunable by a mutual rotation. This optical system is multifocal with at least two sectors with different individually tunable refraction powers. To obtain a monofocal rotation optics, obscuration of one of the lens sectors is necessary. Conventional lens systems providing tunable refraction power do so by mutual axial or lateral shift of the lenses or the lens parts. Hence, additional space for lens movement is needed in the mechanical design. Since the rotational optics allows for adjustment of the refraction power by a mutual rotation of the lens parts, no displacement of lenses is needed and a more compact design is obtained.